Transport apparatus having a measuring system and methods therefor

ABSTRACT

A transport apparatus includes a bearing assembly for transporting an article. The bearing assembly includes a support structure for receiving the article, and a plenum housing for receiving the support structure. The plenum housing and the support structure define a plenum cavity, the plenum cavity being configured to receive and direct a flowing gas for floatingly supporting the article above the support structure. The bearing assembly further includes at least one sensor assembly, which includes a sensor for transmitting and receiving energy emissions for determining a location of the article relative to the support structure. The sensor assembly may determine the location of the article relative to the support structure substantially through at least one aperture located on the bearing assembly. The article location determined by the sensor assembly may be communicated to a display panel or a control unit for adjusting the location if necessary.

This application is a divisional and claims the benefit of priority toU.S. application Ser. No. 12/915,662 filed on Oct. 29, 2010 and entitled“Transport Apparatus Having A Measuring System And Methods Therefor”,which is hereby incorporated by reference for all purposes as if fullyset forth herein.

BACKGROUND

1. Field of the Disclosure

A transport apparatus is disclosed and methods therefor, specifically atransport apparatus that includes a gas bearing having a measuringsystem for determining a location of an article being transported.

2. Technical Field

Such articles of manufacture as extruded logs or extrudates of, forexample, ceramic material are used in a variety of applicationsincluding, for example, substrates for automotive exhaust, as incatalytic converters, particulate traps within diesel engines, andchemical filtration processes. The manufacturing process for theseextrudates typically includes the transfer of an uncured or wet logalong a manufacturing line subsequent to being extruded from anextrusion die.

Transfer of such articles is typically conducted via a process that usessuch non-contact transport devices as, for example, an air bearingassembly on the manufacturing line, which requires an operator tomanually, e.g., visually, determine the log condition, location orheight as it travels along the manufacturing line. Close tolerances onthe log demand proper location, or ride height, to prevent productdamage. However, the distances involved are very small relative to thesize of the article, and visual inspection during transport can bedifficult. Consequently, it is typical for much subjectivity indetermining ride height, and damage to the logs during transport mayresult.

Apparatuses and methods are therefore needed which remove subjectivityassociated with manual, or visual, monitoring of an article duringtransport, for example, an extruded ceramic log or other extrudate on agas bearing, including maintaining an optimum ride height on the gasbearing.

SUMMARY

A transport apparatus includes a bearing assembly for transporting anarticle. The bearing assembly includes a support structure, which has afirst side and a second side, and a surface disposed between the firstand second sides, the surface configured to receive the article. Thesupport structure also has at least one aperture disposed through thesurface.

The bearing assembly also includes a plenum housing for receiving thesupport structure. The plenum housing and the support structure define aplenum cavity, which is configured to receive and direct a flowing gas.

The bearing assembly further includes at least one sensor assembly. Thesensor assembly includes a sensor for transmitting and receiving energyemissions for determining a location of the article relative to thesupport structure. The sensor may be a laser sensor, a magnetic sensor,an electromagnetic sensor, an electrostatic sensor, a capacitancesensor, an ultrasonic sensor, a photoelectric sensor, an inductivesensor, or combinations of the same.

In one embodiment, the sensor assembly may include a base plate forreceiving the sensor, and an adjustment mechanism for adjusting theposition of the base plate and the sensor in relation to the supportstructure. The sensor, for example, may be located proximal to the atleast one aperture, the sensor determining the location of the articlerelative to the support structure substantially through the at least oneaperture. The sensor assembly may be located within the plenum cavity.

A method is disclosed for monitoring and adjusting a location of anarticle in longitudinal motion on a transport apparatus, includingproviding an article and a transport apparatus, the transport apparatusbeing adapted to receive the article on a layer of a gas from a gas flowsource. The method also includes providing at least one sensor assembly,the sensor assembly being configured to transmit and receive an energyemission to sense a location of the article, and to communicate thelocation to at least one control unit. Based upon a comparison to apredetermined range of location values, the control unit may communicateinstructions to at least one gas flow source, increasing or decreasing agas flow to the plenum cavity, changing the location of the article.

Additional features are set forth in the detailed description whichfollows, and in part will be readily apparent to those skilled in theart from that description or recognized by practicing the describedembodiments and the claims, as well as the appended drawings.

It is to be understood that both the general description and thedetailed description are exemplary, and are intended to provide anoverview or framework to understand the claims. The accompanyingdrawings are included to provide a further understanding, and areincorporated in and constitute a part of this specification. Thedrawings illustrate one or more embodiment(s), and together with thedescription serve to explain principles and operation of theembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic layout view of a transport apparatus;

FIG. 2 is a sectioned isometric view of a bearing assembly of thetransport apparatus of FIG. 1;

FIG. 3 is a perspective view of the interior of the bearing assembly,showing part of a sensor assembly;

FIG. 4 is a perspective view of the interior of the bearing assembly,showing part of a sensor assembly;

FIG. 5 is a bottom perspective view of the sensor assembly of FIG. 3;

FIG. 6 is a perspective interior view of the bearing assembly of FIG. 2,showing an alignment fixture; and

FIG. 7 and FIG. 8 are side sectional views of the bearing assembly.

DETAILED DESCRIPTION

Reference is now made in detail to embodiments of the disclosure,examples of which are illustrated in the accompanying drawings. Wheneverpossible, identical or similar reference numerals are used throughoutthe drawings to refer to identical or similar parts. It should beunderstood that the embodiments disclosed are merely examples with eachone incorporating certain benefits of the present disclosure. Variousmodifications and alterations may be made to the following exampleswithin the scope of the present disclosure, and aspects of the differentexamples may be mixed in different ways to achieve yet further examples.Accordingly, the true scope of the disclosure is to be understood fromthe entirety of the present disclosure in view of, but not limited to,the embodiments described herein.

A transport apparatus is disclosed having a bearing assembly fortransporting an article from a first location to a second location. Thebearing assembly includes a support structure for receiving the article,for example, on a layer of gas, and floatingly supporting the article.The bearing assembly further includes a sensor assembly for determininga location of the article, for example, relative to the supportstructure. The sensor assembly may be associated with the supportstructure. The support structure includes at least one aperture; thesensor assembly may utilize the at least one aperture to determine thelocation of the article. The sensor assembly may be in communicationwith at least a display configured to communicate the article locationto an operator. The sensor assembly may further be in communication witha control unit that may provide instructions to a header, valve body, orblower to change the location of the article in response to, forexample, comparison to a predetermined location value or range oflocation values.

A schematic of transport apparatus 10 (FIG. 1) includes an article 11,which may be, for example, a ceramic extrudate log extruded from anextruder 13. In other embodiments, article 11 may be, for example, aglass sheet or an optical fiber. Article 11 may be transported along abearing assembly 20 to, for example, a saw 16, or other cuttingapparatus, where article 11 may be cut into at least one article segment17 of predetermined length. Article segment 17 may be furthertransported along, for example, another bearing assembly 20 to, forexample, a ceramic dryer 12, a storage area, a packing area, or otherpost processing area.

Transport apparatus 10 also includes a system for supplying a gas tobearing assembly 20. Gas flow source 18 supplies a flowing gas, forexample, air, along a valve body gas pipe 19 to, for example, a headeror valve body 15. Valve body 15 supplies at least a portion of theflowing gas along at least one bearing gas pipe 14 to bearing assembly20.

Valve body 15, in some embodiments, may be in communication with acontrol unit 50 that sends a signal along a control cable 51 in responseto data received from a sensor assembly 30 (FIG. 2) associated withbearing assembly 20. Sensor assembly 30 may communicate with controlunit 50 along, for example, a sensor cable 49. Other communicationmethods, for example, wireless, or infrared signals, are possible.

Bearing assembly 20 (FIG. 2) may include, for example, a supportstructure 22 configured to receive article 11 or segment 17. Supportstructure 22 may be configured to receive such article shapes fortransport as substantially flat, substantially cylindrical, elongatedoval, elongated bi-radial ovoid, elongated rectangular, or substantiallysquare shapes. Support structure 22 may be attached to a plenum housing24. A plenum cavity may be defined by the attachment of supportstructure 22 and plenum housing 24. The plenum cavity may be adapted toreceive the flowing gas through an opening surrounded, for example, by agas supply flange 26. Support structure 22 may include a plurality ofgas apertures 23 (FIG. 1). The plenum cavity may direct the flowing gasto pass through gas apertures 23 for floatingly supporting article 11,or segment 17. Gas supply flange 26 may be included on plenum housing 24to influence the rate of gas flow into the plenum cavity by way of aninner diameter or aperture size, and to assist in a secure attachment ofgas pipe 14 to plenum housing 24. Gas apertures 23 are not shown insubsequent drawings for clarity.

Sensor assembly 30 includes an article sensor 32 (field effect sensor),for example, an electromagnetic, or laser sensor. Other field effect arepossible, including, but not limited to, a magnetic sensor, anelectrostatic sensor, a capacitance sensor, an ultrasonic sensor, aphotoelectric sensor, and an inductive sensor. Sensor 32, in exemplaryembodiments, sends, radiates, or otherwise emits a signal or energyemission 33 that may reflect upon a portion of the surface of article11, with at least part of the emission 33 returning to, for example, acorresponding receiver to determine the location of article 11 relativeto, for example, sensor 32, or other reference datum. Emission 33 may bea focused emission, as in, for example, a narrow beam from a lasersensor, or emission 33 may be a more diffuse emission, as in, forexample, a broad emission from a photoelectric sensor. Sensor 32 may bemounted, for example, on a base plate 40 that may place sensor 32 in aposition for most effectively sensing a location of article 11. Inexemplary embodiments, base plate 40 may be placed on an interiorsurface, for example, a floor surface, of plenum housing 26. Base plate40 may position sensor 32 below at least one sensor aperture 28, placingsupport structure 22 between sensor assembly 30 and article 11 orsegment 17. Aperture 28 may be a round hole or a slot. A suitable sensor32 may be selected to accommodate particular space, orientation,environmental, or material requirements. In some embodiments, sensoraperture 28 may be selected from one of gas apertures 23.

In some embodiments, sensor assembly 30 may be placed in such alternatelocations as above, beside, or below bearing assembly 20. Some sensors,for example, may be sensitive to high heat or high humidity, which mayadversely affect sensor performance, making it necessary to place thesensors in alternate locations. In one embodiment, sensor assembly 30may be placed outside of, for example, below, plenum housing 24, placingplenum housing 24 and support structure 22 between sensor assembly 30and article 11 or segment 17 (FIG. 8). Plenum housing 24 may include aplenum aperture 72 for such an embodiment, to enable emission 33 to passcompletely through plenum housing 24, the plenum cavity and aperture 28of support structure 22 to sense the location of the article 11 orsegment 17.

Sensor assembly 30 may include a cover 39 with, for example, a window 37to protect sensor 32 (FIGS. 2 and 4) from such hazards as debris or dirtthat may affect the accuracy of sensor 32. In certain embodiments, baseplate 40 may receive sensor 32, for example, in a side-ways orientationto limit the overall height of sensor assembly 30. In embodiments wherespace allows base plate 40 may receive sensor 32 in other orientations.Base plate 40 may include an inclined surface 42 (FIG. 3) adapted toredirect emission 33 from a first direction to a second direction. Forexample, in one embodiment, sensor 32 may project emission 33 in asubstantially horizontal direction, and inclined surface 42 may redirectemission 33 to a substantially vertical direction. Inclined surface 42may include a reflective surface such as a polished planar surface, ormay be adapted to receive a reflector 44, such as a mirror made frompolished metal or mirrored glass. Window 37 of cover 39 may be a glassplate adapted to permit transmission of emission 33, while notabsorbing, reflecting or otherwise diverting the energy of emission 33.For example, window 37 may be a glass plate having a non-reflectivecoating. Other sensors may use coherent energy or other reflected energyarrangements.

Base plate 40 may include at least one mounting pad 46 (FIG. 5) forcontacting the mounting surface of, for example, plenum housing 24. Inexemplary embodiments, base plate 40 may include three mounting pads 46for a three-point contact to the mounting surface. Mounting pads 46 areadapted to raise a portion of base plate 40 above the mounting surfaceto reduce the actual contact area, insuring greater repeatability forremoval and reinstallation, for example, for servicing any portion ofsensor assembly 30. Mounting apertures 47 may be located throughmounting pads 46 to reduce any twisting or torque effect from mountingbase plate 40 onto the mounting surface. In other words, mounting screwsused to tightly secure base plate 40 to the mounting surface will notadversely affect the structure of base plate 40, presenting base plate40 as a reliable platform for receiving sensor 32. Base plate 40 may bemade from such materials as an aluminum alloy, a steel alloy, a plasticor other suitable materials.

In exemplary embodiments, sensor assembly 30 may be in communicationwith control unit 50 via sensor cable 49. Control unit 50 may be incommunication with valve body 15. In other embodiments, sensor assembly30 may be in communication with a data display, for example, a displayscreen, to inform an operator of the location of article 11 or segment17. Based upon the location data presented to either the operator or tocontrol unit 50, valve body 15, or gas flow source 18 may be adjusted toallow more or less gas flow into gas channel 14 to increase the pressurewithin the plenum cavity. Support structure 22, secured to plenumhousing 24, may allow the higher pressure gas to pass from the plenumcavity to the lower pressure area outside of the plenum cavity throughaperture 28, or gas apertures 23, installed throughout the surface ofsupport structure 22. Pressure within the plenum cavity may be, forexample, from about 1 inch water (inH2O) to about 7 inH2O above thepressure outside the plenum cavity, inducing gas to flow out through theapertures. This may change the location of article 11 or segment 17relative to support structure 22 by reducing or increasing the thicknessof a gas layer 70 (FIG. 7) supporting article 11 or segment 17.

Installing sensor assembly 30 to bearing assembly 20 involves, in oneembodiment, removing support structure 22 to reveal the interior ofplenum housing 24. A template for cutting bolt holes may be placed in adesired location, for example, near a center axis of plenum housing 24,and bolt holes may be drilled, or otherwise cut, into, for example, thefloor of plenum housing 24. A cable aperture 48 to allow ingress andegress of sensor cable 49 may be drilled or cut into, for example, aside wall of plenum housing 24 (FIG. 3). Sensor 32 may be secured tobase plate 40 by means of, for example, provided mounting features onsensor 32. In some embodiments, sensor 32 may be mounted side-ways, sothat emission 33 encounters, for example, reflector 44. In alternateembodiments, where sensor 32 may be in a vertical orientation, emission33 may not encounter a reflector 44. Cover 39 may be installed aftersensor 32 is secured to base plate 40.

Base plate 40 may be placed on the mounting surface, taking care toalign mounting apertures 47 to the corresponding bolt holes on themounting surface. Bolts may be used to secure base plate 40 to themounting surface; however, other such attachment means as screws,push-pins, rivets, and adhesives may be used. Sensor cable 49, beingsecured to either control unit 50 or to a data display unit, may bethreaded through cable aperture 48 and mated to laser sensor 32.

Once in place on the mounting surface, base plate 40 may be positioned,for example, by use of alignment mechanism 60. At least one alignmentmount 62 having an alignment mechanism 60 affixed may be placed on atleast one predetermined location on base plate 40. In some embodiments,three alignment mounts 62, each mount affixed to an alignment mechanism60, may be mounted to base plate 40. Alignment mount 62 may be amachined metal arm, or a molded plastic arm, which is adapted to receivealignment mechanism 60 and attach to base plate 40. Alignment mechanism60 may be a manual micrometer that pushes against a substantiallyunyielding surface while being turned, for example, against a wall,column, or partition found on plenum housing 24, causing a counter forceto move alignment mount 62 as well as anything affixed to alignmentmount 62. Alignment mechanism 60 may also be a servo driven actuatorthat may respond to an electrical or optical signal.

In exemplary embodiments, alignment mechanism 60 (FIG. 6) may beassisted by an alignment fixture 64 to fine tune the alignment of sensorassembly 30. Alignment fixture 64 may be placed along a portion ofplenum housing 24. Alignment fixture may have at least two plates 68,for example, glass plates, situated parallel to each other andsubstantially perpendicular to the desired path of emission 33. Eachplate 68 may be scribed or marked with indicia that, in alignment, maycoincide with the desired path of emission 33, allowing emission 33 topass through aperture 28. Aperture 28, in some embodiments, may be aslotted opening to allow emission 33 to enter and exit from twodifferent angles. Other sensors may require different shaped openings.Once sensor assembly 30 is tuned so that emission 33 may travel in thedesired path, alignment fixture 64 may be removed, and support structure22 may be replaced onto plenum housing 24. In some embodiments, sensorassembly 30 may be installed onto bearing assembly 20 as a retrofittedassembly, requiring, for example, drilling bolt holes in the field, ormanufactured and assembled as an original equipment assembly.

Sensor assembly 30 may be calibrated and a set point established byplacing, for example, an object that closely matches the shape orcontour of support structure 22 over aperture 28, which may approximatea “bottom” of support structure 22. A location may be established forthe “bottom” of support structure 22, and that location may be set,zeroed, noted, or otherwise fixed as a starting location. In anexemplary embodiment, a value recorded for the location of an articlethat is greater than the starting location may be considered a positive“height” above, for example, the bottom of support structure 22. In someembodiments, a value for maximum and minimum height may alert either theoperator by means of a display or an alarm, or control unit 50 by meansof a preset value or range of values, to take action to adjust gas flowinto bearing assembly 20 by, for example, opening or closing valves, orby decreasing or increasing the speed of blower 18. In some embodiments,if the value is above a preset maximum value, article 11 or segment 17,may flutter or vibrate, causing product damage. For example, in anembodiment where article 11 is a ceramic extrudate, the surface orinternal structure of the extrudate may be damaged. In embodiments wherearticle 11 is, for example, a glass sheet, the glass sheet may, forexample, become misaligned from its desired travel path, where it mayencounter objects or another glass sheet and become damaged. If thevalue is below a preset minimum value, article 11 or segment 17 may nottravel floatingly and may actually scrub, rub, or otherwise make contactwith support structure 22, possibly damaging article 11.

In one embodiment, extruder 13 may extrude article 11, which may then becut into segment 17, onto bearing assembly 20. Segment 17 may continuein a longitudinal direction, as indicated by the arrow (FIG. 7). Bearingassembly 20 includes, for example, an air bearing to floatinglytransport the extrudate from the extruder to, for example, ceramic dryer12. As article 11 passes over aperture 28, emission 33, projectingupward through aperture 28 from sensor assembly 30, may encounter aportion of the outer surface of article 11 and reflect a return emissionto sensor 32. Sensor 32, in exemplary embodiments, may calculate thelocation data or height of article 11 based upon the return emission. Inalternate embodiments, a separate processor unit may calculate thelocation data. Sensor 32 may communicate or transmit the acquired datato either a display, as in an open loop feedback system, or to controlunit 50, as in a closed loop feedback system. The open loop feedbacksystem may require monitoring by an operator to manually adjust theheight of article 11 or segment 17. The closed loop feedback system mayautomatically adjust the height of article 11 or segment 17.

In exemplary embodiments, sensor assembly 30 may include a sensor thatmeasures the speed as well as the location of article 11, or segment 17.In addition to communicating with control unit 50 to adjust gas flow,such an embodiment may communicate with, for example, the extruder 13 toincrease or decrease the speed at which the article 11 is extruded ontothe bearing assembly. The speed measurement may be independent of thelocation measurement, for example, using a discrete speed sensor device,or may be done simultaneously using, for example, an integrated speedand location sensor device.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth in the disclosure be construed as requiring that itssteps be performed in a specific order. Accordingly, where a methodclaim does not actually recite an order to be followed by its steps orit is not otherwise specifically stated in the claims or descriptionsthat the steps are to be limited to a specific order, it is no wayintended that any particular order be inferred.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the disclosure. Since modifications, combinations,sub-combinations and variations of the disclosed embodimentsincorporating the spirit and substance of the disclosure may occur topersons skilled in the art, the disclosure should be construed toinclude everything within the scope of the appended claims and theirequivalents.

What is claimed is:
 1. A method of monitoring and adjusting a locationof an article in longitudinal motion on a transport apparatus,comprising: providing an article; providing a transport apparatus, thetransport apparatus adapted to receive the article on a layer of a gasfrom a gas flow source, the gas flow source providing a flowing gas;providing at least one sensor assembly, the sensor assembly configuredto transmit and receive an energy emission to sense a location of thearticle; providing at least one control unit, the control unit being incommunication with the at least one sensor assembly and the gas flowsource; projecting the energy emission from the sensor assembly onto asurface of the article; reflecting the energy emission from the surfaceof the article; receiving the reflected emission by the sensor assembly;calculating the location data by the sensor assembly using the reflectedemission; transmitting the location data from the sensor assembly to thecontrol unit; comparing the location data by the control unit to apredetermined range of location data values; transmitting an instructionsignal from the control unit to the gas flow source in response to thecomparison of the data to the predetermined range of location datavalues; and increasing or decreasing the volume of flowing gas to thetransport apparatus from the gas flow source in response to theinstruction signal from the control unit.
 2. The method of claim 1, thestep of providing the transport apparatus including providing at leastone support structure, the support structure including a first side anda second side, and a surface disposed between the first and secondsides, the surface being configured to receive the article, the supportstructure having at least one sensor aperture disposed through thesurface.
 3. The method of claim 2, the step of providing the transportapparatus including providing at least one plenum housing, the plenumhousing receiving the support structure to define a plenum cavity, theplenum cavity configured to receive and direct the flowing gas.
 4. Themethod of claim 3, including the step of providing a valve body forcontrolling the flowing gas, the valve body in communication with boththe gas flow source and the control unit, the gas flow source providinggas flow through the valve body to the plenum cavity.
 5. The method ofclaim 1, the article being a ceramic extrudate.
 6. The method of claim1, the article being a glass sheet.